Result by Ben Fisch, Daniel Freund, Moni Naor
Blog written by Samuel Ranellucci

The two main goals of this paper are to
Formalize physical protocols for zero-knowledge and to
prove something that cannot be proven digitally.

The paper focus on two tasks: Nuclear disarmament and DNA profile.
The talk focused on DNA profiling.

In this talk, the defendant wishes to prove that his DNA was not the one found at
the crime scene without giving it to police. This protects
the defendant against contamination and against police corruption.

First, a protocol based on the zero-knowledge graph isomorphism protocol was presented.
Essentially by using tamper evident seals and masking tape, first the client
would send a sealed sample, the cop would use one sample
either from the crime scene or the given sample and then send it back.
The defence would then have to determine which sample was taken.
A protocol based on proof of set size relies on weaker assumptions.

When modelling a physical zero-knowledge proof, it is necessary
to go from real world, ideal world and then back to the actual model.

In contrast to standard ZK, physical ZK ideal functionality has no witness.